Answer / shreenidhi

OLTC(on load tap changer)is a mechanism used in transformer
for changing the tapping position on primary side(HV)of
transformer.For any installation mostly in industrial areas
and rural areas the voltage on HV of the transformer will
not be 11kv(taking an example of 11kv System)and
correspondingly the output will not be 433v.To maintain a
constant 11kv/433v the tap changer on the Primary/HV side
of the transformer is either raised or lowered to maintain
constant 11kv input to transformer.Normally it is raised or
lowered in steps of 2.5% of normal KV value.

Answer / rajneesh upadhyay

OLTC means on load tap changer .
By this we can regulate the voltage level of load side
which is always varying but must be constant .
By this we can change the no of turns of hv side so turn
ratio hence voltage level of load side on loaded condion.
tap changing coil is placed over hv and connected to hv to
accurate voltage variation .

Answer / ioan c.

OLTC- as the name said, on load tap changer consist in a
mechanism used in side transformer at HV windings acted
manual or automatic to increase/decrease the ratio HV
voltage requested by the network system to maintain it
between acceptable limits (according to standard)- on load
(without interruption at the HV side voltage), without
disconnect the transformer from the network system, this is
the main important thing. Generally this is done
automatically.

Answer / hin sothea(ctl)

OLTC On Load Tap Changer in Tr. Is mean that the changing
Tap of Transformer is according to the changing of loads
at low voltage side. Any way chang Tap mean chang the turn
winding of Primary side of Tr.
Eg: VL=VHx(NL/NH)
V=P/I

If current at lower side is increased, the voltage at lower
side will be decreased and also for the voltage at higher
side.To make the voltage at lower side stable, the turn
winding at higher side must be higher than it befor. When
the turn is chang it is mean the Tap is chang.

By Ohm Law:

P : Stable
I :→∞
V :→0
VL :constant,Low side Voltage(We need it be constang)
VH :constant,High side Voltage
NL :constant,Low side turn winding
NH :High side turn winding

Answer / raj

OLTC MEANS ON LOAD TAP CHANGER
THE FUNCTION OF OLTC IS TO CHANGE THE VOLTAGE LEVEL OF THE
SECONDARY SIDE OF THE TRANSFORMER ACCORDING TO CHANGE IN
LOAD SIDE TO MAINTAIN THE CONSTANT VOLTAGE WITHIN THE LIMITS
AND ALSO ITS A SAFETY DEVICE.

Answer / manoj kumar behera

OLTC means ONLOAD TAP CHANGER UT CAN BE OPERATED MANUALLY
OR AUTOMETICALLY. TO OPERATE IT IN MANUAL MODE THERE HAVE
CERATIN CONNECTIONS THAT WE HAVE TO GIVE THAT WILL VARY
DEPENDS UPON THE OLTC MAKE WHILE WE WANT TO OPERATE IT IN
AUTOMETIC MODE WE HAVE TO CONNECT IT TO A RTCC PANEL THAT
IS REMOTE TAP CHANGER CIRCUIT.
THE FUNCTION OF OLTC IS TO CHANGE THE TAPS OF A
TRANSFORMER .THAT IS IT ARRANGE CONSTANT OUTPUT ON L.V.
SIDE.

Answer / virendra

for more details check this link

http://en.wikipedia.org/wiki/Tap_(transformer)

Answer / sanjivani mhaske

OLTC is On load Tap Changer to maintain constant voltage at
secondary side according to change in load. Tappings are
provided on HV winding as this winding is outer on the core.
So less insulation will be required. By changing taps on HV
side, we can monitor voltage at secondary side. Basically,
this tapping is provided on HV side because there is high
fluctuation of voltage on HV side (i.e. from supply
company). Tap changing process is done by RTCC (i.e. Remote
Tap Changer Controller). This is installed in HT panel of
transformer. RTCC sends signal to LCP (local control panel)
which is in turn motor rotates it rotor as per signal
received from RTCC. It is generally used for higher capacity
of transformer.

Answer / murali

OLTC is an On Load Tap changing of transformer. which is
keep the voltage(Secondary side) within the Limitation as
per the Load variation by changing the Tap of transformer at
Primary side

Answer / thapelo eric motsitsi

On Load tap Changers are most suitable
for Automatic Changing and can be
modified/Changing taps while its on
load/ Operating and can can be on either
Lv or Hv Depending on the Required load
Voltage.

bsnl tta exam question

0 Answers  

What is the accepted limit to increase the choosen transformer capacity over the load and why ?

2 Answers   Asec,

What is SMPS,How does it works?

4 Answers   Bharti, TCS,

How to size a transformer which will supply power to 550kW,690V motor starting with VFD?

1 Answers  

What happens when reactive power enters a system?

6 Answers  

Hi,Any one has idea regarding the KPTCL Recuirtments for AE'e & JE's for the year of 2009-10???Kindly help in regards..

6 Answers  

Why are calling lagging power factor is a inductive load?

2 Answers  

Why HT motor is connected in Star?

3 Answers   Equate,

how to CHECK CT AND PT AT THE FAULT OCCUR IN GENERATOR RELAY PANEL .

0 Answers   Birla,

in my industry we are using 3 step up transformers for induction heaters..i.e 415/580v and other are 11/440v.in power consumption does a step trnsformer makes any difference compared to step up?? plz explain

0 Answers  

what is the earth resistance

4 Answers   Micron Electricals,

when qty of cable being purchased is not sufficient according to the standard,what should the inspector do to ensure its quality according to the standard?

0 Answers